Self-priming centrifugal mine pump



March 9, 194-3. E PP SELF-ERIMING CENTRIFUGAL MINE PUMP Filed Aug. 2, 1940 P M w N NN 3 QM T. m 5

March 9, 1943. H. E. RUPP PRIMING GENTRIFUGAL MINE PUMP SELF- Filed Aug. 2, 1940 s Sheets-Sheet 2 fimamrf. RUPP.

March 9,- 1943. H. EKRUPP 2,313,585

SELF PRIMING CENTRIFUGAL MINE PUMP Filed Aug. 2, 1940 3 Sheets-Sheet 3 35 gvwam bom Patented; 9, i943 entree stares Pa rs attests caries sum-naming climmrcaai. MINE rum Herbert n. nabs. Springfield romaine,

' Richland County, Ohio Application August 2, race, Serial No. eraser (or. lint-1113).

Claims.

This invention relates to self-priming centrifugal pumps, or to improvements therein, having reference more particularly to suction lift pumps during the selfpriming cycle and becomes inoperative, or substantially inoperative, when the pump is primed or pumping liquid, i. e. a pump in which the action of self-priming is automatic and operable or efiective only when thepump is first started or loses its Prime. 4

Another object is to provide a pump of high efiiciency, having the greatest possible capacity for its size, suitable to various uses and purposes in which heavy duty service with ahigh pressure lift is especially desired and which can be easily assembled or disassembled for the replacement ct parts.

A further object is to provide a pump substantially eliminating the possibility of corrosion and resultant deterioration and adaptable to adjustment to compensateior wear or the enlargement Fi 2 is a back side view of the front impeller casing plate; Y

Fig. 3 is a transverse section of said plate taken on the line 3-3 of Fig. 2;

Fig. 4 is a plan section taken on the linedi of Fig. 2, looking inthe direction of the arrows; Fig. 5 is a front end elevation of the pump, with a modification of discharge connection, a part of the same being broken away to reveal the interior;

Fig. 6 is a section taken on the line 6-6 of Fig. 1, looking in the direction of the arrows; and a Fig. 7 is a fragmentary section taken on the line 1-7 of Fig. 5.

In the illustrative embodiment, the'main body 7 of the pump is formed by the casing 10, which is open at its rearward side.

formed with an inlet opening I I in its forward side near the top, from which an L-shaped inlet a passage l2 leads downward directly into the axis or eye of the impeller, leaving a circular space 7 l3 therearound providing-the liquid chamber in which air and liquid separation takes place. Said inlet opening is controlled by a valve l4 closing upon a seat is formed by a coupling nipple l6 adapted .to connection. with the usual suction or intake hose H. In its top or upper side, the

. casing is formed-with a. discharge opening l8 to or clearance between the pump rotor and its surrounding casing or volute, the several parts being oi simple construction reducing the amount or foundry and machine such parts less expensive than a more oomphcated construction.

The aforesaid objects contemplate a generally improved construction or organization in an otherwise common type known to be best suited for the work for which it is primarily intended.

simplicity and compactness, together-with ac-- cessibility and ready replaceabflity of parts, are further objects sought in this connection.

As the particular conceptand other purposes,-

in addition to the general advantages of the inventiori, will be best understood from further de scription with reference to illustration-it will be described and explained hereinafter in detail with reference to the attached drawings showing in diflerent views one practical embodiment of the invention model.

In said drawings:

Fig. 1 is a. longitudinal section or the pump; 55 '1 as produced in an actual working shop work necessary to produce it and rendering the replacement of.

which the usual discharge pipe I9 is connected. At its bottom, a plug 20 closes the usual drain hole. 1

The back side of said casing is closed by a plate 2! of the peculiar form illustrated by Figs. v

2 to 4, wh ch forms a part of the impeller housing or volute and in fact itself virtuallyconstitutes said volute. This plate is fitted circumferentially against the open side of said casing with a gasket 22 disposed therebetween and is secured ning point 25 close to the' by a clamping arrangement to be later described.

The central part of said plateis formed into a forwardly extending open neck or annulus M fitting around the open end of the passage l2 shouldered for that purpose, a ring washer or gasket 23 being interposed therebetweento eliminate any leakage. It sitioning by an integral lu 2| fitting between lugs or shoulder faces I2 on the inlet passage.

The intermediate portion or wall of the plate is formed, with an outward bulge or concavitation indicated at 2l around the central opening, to provide a volute channelor space 24 on its inner or back side, having the usual cut-01f or beginimpeller periphery and the usual discharge or mouth 26,-1ocated in this instance below said cut-oil; at the bottom This casing is is disposed and heldto poof the main pump chamber. Said discharge of course opens into the liquid chamber IS, in this instance at the bottom of the same. Being immediately below the cut-off in this present construction, said cut-off also is located at the bottom of the pump casing. Immediately above the level of the cut-off, an arcuate slot opening 21 is provided in the plate to allow for the return or recirculation of liquid from the liquid champassag provided thereby has a different volute form or space extent, or a different volute char acteristic. The capacity can be'changed also by employing different forms of impellers. When changing the plate itself therefore, it would be desirable to also change the impeller. It is a simple matter to change this plate to so alter the capaciy as desired, its general form however being otherwise substantially the same, including the described hooded slot opening 21.

The open rearward side of the volute plate 2| is closed by a second or seal plate 28, which accordingly also closes the back end of the pump body. This seal plate 28 is circumferentially fitted against the outer face of the former plate with a. gasket 29 disposed therebetween and, like the firstmentioned'plate, is secured in place by a clamping arrangement to be later described.

'It is formed with a central boss or neck 28 through which the shaft of the impeller extends with a suitable packing or stumng box 30 therearound, but as the latter constitutes no essential part of the present construction it is not described in detail, particularly inasmuch as the component parts are clearly shown, including the usual lubricating attachment 3| by which the -said packing is kept properly lubricated and is in this instance formed with a forward protuberance 33' over its fastening or threading upon the end 'of said shaft and hoods or caps the same from contact by the liquid. Also, in combination withthe shaping of the inlet passage and neck of the volute plate 2 I, this protuberance provides a center directloning guide for liquid into the impeller blades. It will beunderstood that the tips of the blades or vanes of this impeller sweep close to the cut-0E point 25 of the volute passage 24 formed between said plates 2| and 28 as is typical in pumps of this character,

its rotation in this instance being counter-clockwise as viewed from Fig. 5, orclockwise as viewed from'Flg. 2. It will be also understood that said impeller is mounted in place on its shaft between the plates before the same are secured in their clamping arrangement to the main body part or casing ||I of the pump. 4

The entire pump body, including the volute and seal plates 2| and 28, is coupled to a pedestal block or bracket member 35, with said plates and their interposed gaskets clamped between said member and the main pump casing part II, as shown in Fig. '7. This coupling is effected in conventional manner by bolts 36 passed through lugs Hi and 35 respectively on the main body and pedestal parts, which are drawn up tight to seal said parts securely together. Simultaneously with this tightening, the-aforementioned washer or gasket ring 23 fitted between the inlet passage and neck of the volute plate is comter extends, and is closed at its opposite ends by closure plates 4| and 42. .In effect, this sleeve comprises a closed cartridge carrying the shaft support bearings and therefore indirectly supporting said shaft. Its outer end is formed with a lug 38- carrying a set screw 43 bearing against the back wall of the pedestal or bracket member so as to b retained in adjusted position. This adjustability of said carrier sleeve is of vital importance in a mine pump construction, because of the corrosiveaction of mine water which in many instances has a tendency to reduce the thickness of the impeller vanes, thereby increasing the clearance between said vanes and the adjacent part or wall of the volute plate 2|, thus materially reducing the pump capacityand pumping effect. This can be readily restored to its original capacity, in the present construction, by loosening the clamp bolts 39 and moving the entire cartridge or sleeve 38 forwardly, thereby also moving the shaft and impeller in the same direction. To do this of cours the set screw 43 must first be loosened. In effecting this movement for the stated adjustment, said cartridge or sleeve is pressed forward until the impeller touches or frictions against the wall of volute plate 2|, as can be readily determined byv turning the shaft 34 by hand. It is then drawn rearward just enough to permit the impeller to turn free with the proper clearance between it and said plate, whereupon the set screw 43 is adjusted back to place to hold the parts in precise adjustment and the bolts 39 are again tightened to hold the car tridge or sleeve against movement in either di rection; Thus, easy adjustment of the clearance can be made without the necessity of dismantling the pump. I

With reference to corrosion from the pumped liquid, some metallurgists contend that it does not occur very readily and does not attack one part or one particular surface of metal more than another." However, practical experience has shown that corrosion does often occur, particularly in the pumping of mine water and that this corroflon occurs more especially upon threaded and machined parts and particularly at regions where sharp edges or corners exposed thereto occur. The fact is that almost any Dump used in '-mine operation eventually corrodes or wears down suiliciently to substantially reduce its apacity and effective work. Therefore, it is decidedly desirable to have a pump which can be readily adjusted to compensate for or close this increased clearance. It is also desirable to have a pump which is free of points' or sharp edges advantage applies also to acid liquids involved escape of priming water from the pump, but

- opens to allow free entry of water through the suction line.

It should be added that the pump is adapted to high speed operation, i. e. the impeller is in-' tended to be rotated at speeds of 3000 R. P. M. or more, up to 6000 or 7000 R. P. M. Its shaft 34 s is represented with a key-way 46 adapting it to in other operations, or to liquids which are decidedly corrosive in character.

In the modification of Fig. 5, the discharge pipe i9 is substituted by'an elbow connection l9 from which'an ordinary discharge pipe 89" extends horizontally rather than vertically. This connection may be made to the left or to the right, as indicated in dotted lines in said view and the said dischcarge pipe can of course be led to any point desired. While the pump will ordinarily be filled with priming water at some point through the regular discharge l9, 8. filling connection or elbow 044, closed by a cap plug 45, is shown in this view through which the priming liquid may be supplied.

In operation, the pump functions substantially the same as the pump described in myaforementioned joint patent with James C. Gorman, No. 2,181,792. That is, the liquid supplied through the inlet passage and entering into the center of the impeller is thrown outby the impeller action into the volute passage or channel 24 and-through its discharge mouth or passage 26 into the liquid chamber it of the pump casing. Here the air present in the volute chamber and drawn thereinto from the suction inlet is released and expelled out upwardly through the discharge connection l9. To replace the liquid connection with a pulley or driving gear. It is of course driven by connection with any suitable power source (not shown), such as a motor or gas engine. Said connection may be of any desired form, either direct or by a clutch cou pling, or indirect as by a belt pulley or gear attachment as stated. However, an ordinary direct clutch coupling will be generally preferred,

both for power conservation and for compactness in unit assembly.

The advantages of the invention or pump construction herein described will be appreciated from its nature and what has been stated. There are three particularly noteworthy advantages, aside from others which will be self-evident. These are: First, that the priming is more effective, due to the formation and location of the slot passage 26 in the volute andto the shroudingof .said passage so that the water drawn therethrough will be taken from the bottom of the chamber 83 where it is most free from air. Second, that the pump is'easily assembled and its parts are of the simplest construction for machine shop as well as foundry work, thereby making replacement of parts much less expensive driven out of the impeller chamber by action of the impeller, liquid from the bottom of the chamber i3 is drawn through the arcuate slot opening 27, above the cut-off point, into the impeller toward its center and this lndrawn or return flow of water is similarly expelled out by force of the impeller blades. The water driven out carries with it a certain amount of air from the impeller center until all air therefrom has been exhausted both from the impeller chamber and from the suction intake, whereupon the pump willstart pumping operation like any ordinary centrifugal pump and the return flow of water through the passage 26 will cease, or substantially cease.

A particular advantage of this construction is that water returned through the opening at is drawn from the bottom of the chamber is rather than from a higher level, due to the shroudingor hooding effect of the bame 28 Thus, the water so drawn is more solid and assured to be free of air discharged through the volute mouth. Similarly, water which fills the volute passage around the operating impeller is more solid or free of air than water in or near its center. 'Accordingly, a rapid discharge of air is assured from the impeller center so as to quickly prime the pump by rapidly expelling all air within the impeller chamber and suction intake. Once the prime has been established, the pump is ready for pumping operation and automatically starts said operation with full capacity. As there are no points for leakage, it will hold its prime indefinitely, unless the suction is broken by air drawn through the suction line. In this connection, the float valve 50 functions to prevent the such adjustment is definitelydetermined without dismantling of the pump or any of its parts; also, this adjustment after being once made is securely held in position by means ofthe clamp action of the bolts 30 and the set of the screw 43. To the foregoing should be added the decided advantage of a substantially corrosive-proof pump, or a pump in which parts ordinarily subject to attack by corrosion are notably absent or shielded from contact with the pumped liquid.

Itwill be understood that certain changes can be made in the general'organization and in the form or arrangement of the several parts of the pump, without departing from the spirit and scope of the invention. Certain of such changes Having thus described my invention, what I 1 claim as new and desire to ent of the United States is:

secure by Letters Patl. A self-priming centrifugal liquid pump, comprising an air and liquid separating chamber having a pump intake passage therethrough and an outlet connection, an impeller chamber connected with said intake passage and disposed adjacent to the first chamber and discharging thereinto, an impeller in the impeller chamber carried on an operating shaft for connection with means for driving the same, and a pedestal member supporting the two chambers together with said impeller and shaft, said air and liquid separating chamber being formed in an open-sided main body casing and said impeller chamber being formed wholly by opposed plate parts, one of which constitutes a closure for and whole side of said main body casing and separates the latter chamber from the first and itself substantially forms the liquid discharge passage around the impeller and outlet therefrom into said separating chamber and has an auxiliary inlet to the impeller chamber for return of priming liquid from the separaitng chamber, together with a baflle portion hooding over said inlet, the two plate parts being clamped and held in place between said main body casing and the pedestal member of the pump.

2. A self-priming centrifugal liquid pump, comprising an air and liquid separating chamber having an outlet connection, a pump intake passage leading directly into the axis of the impeller, an impeller chamber of volute form connected with said intake passage and disposed adjacent to the first chamber and discharging thereinto, said impeller chamber being formed wholly by two plate parts, one of which separates said impeller chamber from said separating chamber and itself substantially forms the volute passage around the impeller space and outlet therefrom to the separating chamber, said one of the plate parts having an arcuate inlet adjacent to the impeller periphery and just in advance of the point of discharge from the impeller chamber through which inlet priming liquid returns to the impeller chamber from the separating chamber, together with a bailie portion hooding over said inlet forming a passage thereto from the bottom of the separating chamber, an impeller in said impeller chamber carried on a shaft for connection with means for driving the same, and a support for the two chambers and shaft carrying the impeller, the said plate parts being clamped between said support and that part of the pump casing which contains the separating chamber;

3. A self-priming centrifugal liquid pump, comprising an air and liquid separating chamber having an outlet connection, and an impeller chamber beside the first chamber and discharging thereinto, an impeller in the impeller chamber, said impeller chamber having a main inlet and an auxiliary inlet comprising a lateral arcuate slot in the wall between said chambers arranged adiacent to th impeller periphery just in advance of the point of discharge therefrom, through which inlet priming liquid returns to the impeller chamber from the separating chamber, and a baille hooding over said slot and with said wall forming a passage extending from the extreme bottom region of the separating chamber.

4. In a self-priming centrifugal pump having an impeller chamber and an air and liquid separating chamber into which the former discharges, a separable casing comprising a removable plate and-casing parts between which it is clamped and with one of which it forms the impeller chamber while the other forms therewith the separating chamber, an impeller in said impeller chamber having a back plate; and said removable plate having formed, therein the ain channel for liquid passing through the impeller chamber and around the impeller periphery into the separating chamber and having cut-off means at said periphery, one lateral wall only of such channel being formed in a plane perpen dicular to the impeller axis and forming a continuation of the back plate of the impeller by the first mentioned complemental casing part.

5. In a self-priming centrifugal pump having an impeller chamber and an air and liquid separating chamber into which the former discharges, a separable casing comprising a removable plate and casing parts between which it is clamped and with one of which it forms the impeller chamber while the other forms therewith the separating chamber, an impeller'in said impeller chamber having a back plate; and said removable plate having therein a central intake opening and having the main channel for fluid discharge from the impeller periphery to the sepa- 7 rating chamber and having cut-off means at:

such periphery, one lateral wall only of such discharge channel being formed in a plane perpendicular to the impeller axis and forming a continuation of the back plate of the impeller by the first mentioned complemental casing part, there being in the other casing part a, passage for connection with the pump suction line and from which the impeller takes in fluid at its parts between which it is clamped and with one of which it forms the impeller chamber while the other forms therewith the separating chamber, an impeller in said impeller chamber having a back plate; said removable plate having therein main and auxiliary inlets to the impeller chamher and the main channel for fluid discharge from the impeller periphery to the separating chamber and having cut-off means at said periphery, one lateral wall only of such discharge channel being formed in a plane perpendicular I to the impeller axis and forming a continuation of the back plate of the impeller by. the first mentioned complemental casing part, there being in the separating chamber casing a passage from which the impeller takes in fluid through said main inlet and said auxiliary inlet being in communication with said separating chamber.

'7. A self-priming centrifugal pump of the type and construction set-forth in claim 6, wherein said plate is formed on the side thereof ex-' posed in the separating chamber with a battle ho'oding over said auxiliary inlet whereby priming liquid admitted to the inlet is drawn only from the bottom of the separating chamber.

8. In a self-, priming centrifugal pump, a support, a pair of separate plates forming between them the impeller chamber, and a casing section between which and said-support said plates are clamped and which with the adjacent one of said plates forms an air and liquid separating chamber into which the impeller chamber dis- I charges through opening in said one of said plates, it constituting the partitioning wall between said chambers, an impeller in said impeller chamber having a back plate, there being in said casing section a passage for connection with the suction line of the pump from which the impeller takes in fluid at its central portion through an opening in said one of said plates, the main channel for fluid discharge from the impeller periphery to said separating chamber and cutoil means at said periphery being formed in said one of said plates except only one lateral wall of such channel in a plane perpendicular to the impeller axis which is formed by the other of "separating chamber, into which the impeller said plates and which forms a continuation of the back plate of the impeller. v

9. In a self-priming centrifugal pump, a support, a pair of separate plates forming between F them the impeller chamber, and a casing sec-- tion between which and said support said plates are clamped and which with the adjacent one of said plates forms an air and liquid separating chamber into which the impeller chamber discharges through an openingin said plate and from which priming water returns, to the impeller chamber through another opening in said plate, the latter plate having therein all inlet and outlet openings of the impeller chamber and the main channel for fluid discharge from theimpeller periphery to said separating chamber and having cut-off means at said periphery, an impeller in said impeller chamber having a bacbplate, and one. lateral wall only of such discharge channel being provided in a plane perand wherein priming liquid recirculates to the' impeller onlyfrom the extreme bottom of said chamber discharges, the construction wherein said impeller chamber discharges from its lower part. into the lower part of said separating chamher in a direction to cause the discharging liquid to swirl upwardly in said separating chamber separating chamber, the region in the bottom of the separating chamber from which the liquidso recirculates being just in advance of the point of 4 discharge from the impeller chamber into the pendicular to the impeller axis and substantially in alignment, with the back plate of the impeller by the other of said plates.

10. In a self-priming centrifugal pump having an impeller chamber and an air and liquid separating chamber and the direction of such extreme bottom of the said separating chamber.-

HERBERT E. RUPP. 

